WorkCover NSW has launched an investigation into a 30-year-old's death at Southern Steel Supplies in Milperra early on Monday morning.
Paramedics were called to the facility on Horsley Road at 6.30am after reports that a man had been critically injured when he was struck by a large magnet that was attached to a crane.
Colleagues of the man, who was bleeding heavily, performed CPR until emergency services arrived.
The man was taken to Liverpool Hospital, but died a short time later.
A WorkCover NSW spokesperson said inspectors were at the facility and had launched an investigation.
"Initial enquiries indicate the 30-year-old male worker sustained critical head injuries when he was struck by a crane magnet device. The worker later passed away from his injuries," the spokesperson said.
Police have been contacted for comment.